Threadless side fastener chain

ABSTRACT

Slide fastener chains having filamentary stringers with a plurality of head elements interconnected to a plurality of heel members are formed by disposing the stringers along longitudinal edges of carrier tapes and threadlessly bonding the heel members with the carrier tapes. Projecting portions of the tapes extend more than one half way into interstices formed by the heel members so that the filamentary stringers are firmly attached to the tapes.

United States Patent Moertel 1 Sept. 30, 1975 [54] THREADLESS SIDE FASTENER CHAIN 3.517.422 6/1970 Uhrig 24/205116 C [75] Inventor: George B. Moertel, Conneautvillc,

Primary E.\'aminerBernard A. Gelak [73] Assignee: Textron, Inc., Providence, R1.

[22] Filed: Aug. 21, 1974 21 Appl. No.: 499,232 [57] ABSTRACT Related US. Application Data Continuation-impart of Ser. No. 225.146, Feb. 10.

1972, which is a continuation-in-part of Ser. No. 64,487, Aug. 17. 1970. abandoned.

US. Cl. 24/205.l6 C; 24/205.l3 C Int. Cl. A44b 19/42; A44b 19/10 Field of Search24/205.l6 C, 205.1 C, 205.13 C

References Cited UNITED STATES PATENTS Swainson 24/205.l C

Slide fastener chains having filamentary stringers with a plurality of head elements interconnected to a plurality of heel members are formed by disposing the stringers along longitudinal edges of carrier tapes and threadlessly bonding the heel members with the carrier tapes. Projecting portions of the tapes extend more than one half way into interstices formed by the heel members so that the filamentary stringers are firmly attached to the tapes.

19 Claims, 6 Drawing Figures US. Patent Sept. 30,1975 Sheet 1 of2 3,908,241

U.S. Patent Sept. 30,1975 Sheet 2 of2 3,908,241

THREADLESS SIDE FASTENER CHAIN CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of my pending application Ser. No. 225,146 filed Feb. 10, 1972, which is a continuation-in-part of my. application Scr. No. 64,487 filed Aug. 17, 1970 which is now abandoned. Said applications Nos. 225,146, and 64,487 are hereby incorporated by reference herein.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention pertains to slide fastener chains and more particularly to threadless slide fastener chains wherein the stringers are directly bonded with the carrier tapes.

2. Description of the Prior Art Numerous slide fasteners utilize coupling elements of the type formed from a continuous length of filamentary material which has been deformed into a series of head elements interconnected to first and second sets of generally U-shaped heel members by a plurality of legs. Such a continuous filamentary stringer is commonly referred to as a ladder-type stringer and may be manufactured from any suitable plastic material which, after being formed, can be conveniently attached to a carrier tape.

Generally, in manufacturing a slide fastener incorporating this type of stringer, the stringer is disposed with the head elements aligned next to a longitudinal edge of a carrier tape with the plurality of legs and the first and second sets of heel members overlying respective opposite surfaces of the tape. The plurality of legs of the filamentary stringers are thereafter attached to the carrier tape by suitable stitching or braiding which typically passes through the carrier tapes and around the exposed outer surface of each of the legs to securely affix the stringer to the tape in such as position that the protruding head elements from a pair of filamentary stringers may be easily interengaged for effectively joining a pair of carrier tapes. The resulting interengaged article, which is commonly referring to as slide fastener chain, is then processed through a series of subsequent operations to produce individual finished slide fasteners of a given size or length.

Slide fasteners of the type just described have proven to be highly satisfactory under various conditions of use and as a result have received widespread commercial acceptance. However, in a number of applications such slide fasteners are exposed to considerable surface abrasion on both inner and outer surfaces thereof which has a tendency to sever, tear or otherwise damage the exposed stitching threads. As can be readily appreciated, abrasion of the stitching threads tends to free the stringers from the tapes which often results in misalignment of the interengageable head elements and can cause the slide fastener to jam or to undesirably open at the point of thread wear.

The prior art. as exemplified by US, Pat. Nos. 3,054,364, No. 3,490,098, No. 2,497,821 and No. 3,063,120, Canadian Pat. No. 709,551, France Ire Addition No. 73,252 of Pat. No. 761,179, France Pat. No. 1,280,111 and Great Britain Pat. Specification No. 1,229,600 is generally cognizant of various techniques for attaching filamentary stringers to carrier tapes;

however, a practical and effective threadless slide fastener chain has not heretofore been available.

SUMMARY OF THE INVENTION a threadless slide fastener chain wherein heel members of a filamentary stringer are attached to a carrier tape more securely and firmly than has heretofore been possible.

Another object of the present invention is to ultrasonically fuse the heel members of a filamentary stringer with a carrier tape to form a threadless slide fastener chain.

The present invention has an additional object in the construction of an improved threadless slide fastener chain wherein portions of a carrier tape are displaced into the interstices of a filamentary stringer and are rigidly bonded thereto to form a chain with improved wear characteristics.

A further object of this invention is to attach a filamentary stringer to a carrier tape by bonding superimposed filamentary stringerportions to each other through a carrier tape.

The present invention is generally characterized in that a threadless slide fastener chain includes a carrier tape, a stringer formed from a filamentary material and having a plurality of head elements and a plurality of heel members interconnecting the plurality of head elements, the stringer being disposed along a longitudinal edge of the carrier tape with the plurality of heel members overlying a side surface of the carrier tape, the heel members having leg portions forming interstices therebetween, the carrier tape adjacent the longitudinal edge having portionsprojecting into the interstices of the stringer by at least one-half of the thickness of the portions of the filamentary material forming the heel portions, and each of the heel members being threadlessly bonded with the carrier tape whereby the stringer is firmly attached to the carrier tape.

Some advantages of the present invention reside in its simplicity of construction, economy of manufacture, ability to withstand considerable surface abrasion without being damaged, and the improved strength of the threadless attachment of the stringer to the carrier tape.

Other objects and advantages of the present invention will become apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial plan view of an embodiment of a threadless slide fastener chain according to the present invention;

FIG. 2 is a partial sectional view taken on line 2-2 of FIG. 1;

FIG. 3 is a partial cross-section taken on line 3-3 of FIG. 1;

FIG. 4 is a partial plan view of a second embodiment of a threadless slide fastener chain according to the present invention;

FIG. 5 is a partial sectional view taken on line 55 of FIG. 4; and

FIG. 6 is a partial cross-section taken on line 66 of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. l-3, the present invention is embodied in a threadless slide fastener chain, indicated generally at 10, having a pair of carrier tapes 12 and 13 upon which are disposed a respective one of a pair of filamentary stringers l4 and 15. The filamentary stringers l4 and 15 are substantially identical and are each preferably formed from continuous lengths of plastic filamentary material which have been deformed into a series of head elements 16 and 17, respectively. The head elements 16 and 17 of each series are interconnected by respective first sets of generally U-shaped heel members 18 and 19 and by respective second sets of generally U-shaped heel members 20 and 21. The first sets of heel members 18 and 19 have respective generally straight parallel leg portions 22 and 23 forming interstices therebetween; and the second sets of heel members 20 and 21 have respective generally straight parallel leg portions 24 and 25 forming interstices therebetween. The filamentary stringers l4 and 15 are each disposed along a longitudinal edge of one of carrier tapes l2 and 13 with the first and second sets of heel members overlying respective opposite surfaces of the carrier tapes as illustrated in FIGS. 2 and 3. The stringers thus straddle the edges of the carrier tapes with the head elements 16 and 17 aligned in parallel relationship with such edges whereupon they may be easily interengaged as shown in FIG. 1.

The carrier tapes 12 and 13 are generally flat except adjacent their inner longitudinal edges where they are each displaced upwardly and downwardly at spaced points along the edge to form projecting portions 32 extending into the interstices bounded by the leg portions 22 and bottom portions of heel members 18, projecting portions 33 extending into interstices bounded by the leg portions 23 and bottom portions of the heel members l9, projecting portions 34 extending into the interstices bounded by the leg portions 24 and bottom portions of the heel members 20, and projecting portions 35 extending into the interstices bounded by the leg portions 25 and bottom portions of the heel members 21. The edge of the carrier tape is thus convoluted as can be visualized in FIG. 2 with each displaced portion of the tape forming a raised surface conforming precisely to the interstitial dimensions ofthe legs and heel members of the stringers. The projecting portions, 32, 33, 34 and 35 extend into the interstices by at least onehalf the thickness of the leg portions 22, 23, 24 and 25 to form abutments retaining the heel members 18, I9, 20, and 21. The projecting portions 32, 33, 34 and 35 can extend to full penetration into the interstices, i.e., to where the upper carrier tape surface portions of the projecting portions 32, 33, 34 and 35 lie in the planes defined by the outermost surfaces of the leg portions 22, 23, 24 and 25.

It should be understood that the carrier tapes may take any number of forms depending upon the particular contemplated application of the finished slide fasteners. For example, such tapes may be woven or sewn flat and subsequently deformed, either prior to assembly with the stringers or concurrent therewith. or may be woven to assume its distorted edge shape without requiring a subsequent displacing step. The tapes may also be of the nonwoven type wherein the various fibers used therein are bonded or fused together to form flat strips of material in accordance with any number of well known manufacturing techniques.

Each of the filamentary stringers are attached to the carrier tape in its displaced shape by directly bonding the generally U-shaped heel members of the stringer to the arcuate raised surface of the carrier tape with the fused portion 26 being diagrammatically illustrated in the drawings. It can be seen that by directly bonding the stringers with the carrier tape. the slide fastener chain requires no stitching threads and is thus capable of withstanding considerable surface abrasion which would otherwise sever or tear the stitching employed in conventional slide fastener chains.

Such bonding may be accomplished by any of a number of techniques including, for example, the use of adhesive, dielectric heating, irradiation or ultrasonic fusing. If ultrasonic fusing, for example, is employed to produce the bond, the filamentary stringers as well as the carrier tapes are preferably constructed so as to contain a suitable thermoplastic or fusible material. The ultrasonic energy is thereafter directed through the U-shaped heel members of the stringer and the carrier tape such that a bond of sufficient strength will be formed at the area of contact between the tape and the stringer to assure positive attachment therebetween. It is noted that the strength of such bond is enhanced by the projecting portions 32, 33, 34 and 35 of the tapes which provide relatively large surface areas of contact between the tapes and the heel members of the stringers. Furthermore, the projecting portions 32, 33, 34 and 35 of the tapes become rigidized in the interstices during bonding whereupon the abutments formed by the projecting portions engaging the bottom portions of the heel members tend to prevent separation of the stringers from the tapes due to lateral forces. Longitudinal displacement of the head elements 16 and 17 relative to the tapes 12 and I3 is substantially retarded by the engagement of the projecting portions 32, 33, 34 and 35 with the leg portions 22, 23, 24 and 25.

When the projecting portions 32, 33, 34 and 35 are formed by displaced portions of the total thickness of the carrier tapes 12 and 13 into the interstices, the displaced portions form folds which allow the leg portions 22, 23, 24 and 25 to bend apart when a slider (not shown) opens the slide fastener; such folds substantially preventing stress and breakage of the bonds formed between the heel portions and the tapes and imparting improved flexibility to the filamentary stringers and the edge portions ofthe carrier tapes bonded to the stringers As mentioned above, the carrier tapes may be of any suitable type such as a nonwoven material. Such nonwoycn carrier tapes have an inherently high degree of elasticity which makes them especially well suited for use in the threadless slide fastener chain according to the present invention. This is primarily due to the fact that the elasticity of the nonwoven tape permits the tape to deform somewhat under the force of a point load applied to one of the head elements ofthe stringer; as a result, the point load is distributed to adjacent elements whereupon it can be absorbed without causing damage to the slide fastener chain.

Referring now to FIGS. 46, there is illustrated a sec ond embodiment of a threadless slide fastener chain according to the present invention. The threadless slide fastener chain of FIGS. 46 is similar to that of FIGS.

1-3 and identical numerals with 100 added thereto will be used to describe correspondingly similar structure.

In the slide fastener chain illustrated in FIGS. 4-6, the carrier tapes 112 and 113 each define a set of spaced holes 130 and 131 therethrough which are aligned in parallel relationship with the longitudinal edge of the tape. Each of the holes are cut through the tape in such a position as to be interposed between an end of adjacent members 118 and 119 and 120 and 121, respectively. The carrier tapes are initially not displaced or convoluted as in the'preceeding embodiment but are generally flat throughout. The filamentary stringers are then placed on the tapes so as to straddle the perforated edge of the tape with the ends of the U- shaped heel members aligned with the holes. The heel members are thereafter held together with the ends of adjacent heel members in contact as illustrated in FIGS. 5 and 6 whereupon they are bonded together as by adhesives, ultrasonic fusing, etc., in a manner similar to that described with respect to the preceeding embodiment, with the fused portion 126 being diagrammatically illustrated in the drawings. In this manner, the ends of adjacent upper and lower hell members of the stringers are positively bonded or fused together such that the stringers are firmly attached to the carrier tapes without the use of stitching threads, braiding, or the like.

It should be noted that, as before, the particular carrier tape employed in theslide fastener chain of FIGS. 4-6 may be either woven or nonwoven and may or may not contain thermoplastic or other fibers depending upon the contemplated use of the finished slide fastener. The tapes are distorted, during the bonding, in order to provide a larger bonding surface between the stringers and tapes. The projecting portions 132, 133, 134 and 135 extend into interstices not bounded by bottom portions of heel members 118, 119 and 120 and 121, but between leg portions 122, 223, 134 and 125.

Thus, threadless slide fastener chains according to the present invention are simple in construction, are economical to manufacture, do not require the use of stitching threads, braiding, or the like, and effectively withstand a degree of surface abrasion which would otherwise produce undesired tearing of conventionally employed stitching threads and resultant premature failure thereof.

Inasmuch as the present invention is subject to many variations, modifications and changes in detail, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In a threadless slide fastener chain, the combination comprising a carrier tape,

a stringer formed from a filamentary material and having a plurality of head elements and a plurality of heel members interconnecting the plurality of.

head elements,

said stringer being disposed along a longitudinal edge of the carrier tape with the plurality of heel members overlying a side surface of the carrier tape,

said heel members having leg portions forming interstices therebetween,

said carrier tape adjacent the longitudinal edge having portions projecting into the interstices of the stringer by at least one-half of the thickness of the portions of the filamentary material forming the heel portions, and

each of said heel members being threadlessly bonded with the carrier tape whereby the stringer is firmly attached to the carrier tape.

2. The invention as recited in claim 1 wherein said carrier tape comprises a material containing thermoplastic fibers.

3. The invention as recited in claim 2 wherein said material is woven.

4. The invention as recited in claim 2 wherein said material is nonwoven.

5. The invention as recited in claim 2 wherein said filamentary stringer comprises a thermoplastic material, and wherein said heel members are fused with said carrier tape.

6. The invention as recited in claim 1 wherein said projecting portions of the carrier tape are formed by displaced portions of the thickness of the carrier tape at regularly spaced intervals adjacent said longitudinal edge to conform to the interstices defined by each of said heel members.

7. The invention as recited in claim 6 wherein said carrier tape is initially formed flat and subsequently deformed to produce the displaced portions.

8. The invention as recited in claim 6 wherein said carrier tape is initially formed with the displaced portions.

9. The invention as recited in claim 6 wherein said heel members are rigidly bonded to the projecting portions of the carrier tape.

10. The invention as recited in claim 1 wherein said heel members are generally U-shaped to define bottom portions extending between adjacent leg portions of the heel members, and

said leg portions and bottom portions of the heel members extend around the projecting portions of the carrier tape.

11. In a threadless slide fastener chain, the combination comprising a carrier tape,

a filamentary stringer having a plurality of head elements and a plurality of generally U-shaped heel members with leg portions interconnecting the plurality of head elements,

said stringer being disposed along a longitudinal edge of said carrier tape with a first set of the plurality of heel members on one side of the carrier tape and with a second set of the plurality of heel members on the other side of the carrier tape,

said filamentary stringer having first interstices between the leg portions of the first set of heel members and having second interstices between the leg portions of the second set of heel members,

said carrier tape adjacent the longitudinal edge having projecting portions extending into the first and second interstices by at least one-half of the thickness of the leg portions of heel members,

each of said first and second sets of heel members being threadlessly bonded with said carrier tape whereby said filamentary stringer is firmly attached to said carrier tape such that the projecting portions of the carrier tape are retained in the first and second interstices.

12. The invention as recited in claim 11 wherein said filamentary stringer and said carrier tape both com- 15. The invention as recited in claim 11 wherein the ends of adjacent heel members on the one and other sides of the carrier tape are bonded together through said carrier tape.

16. The invention as recited in claim 15 wherein said filamentary stringer comprises a thermoplastic material, and wherein the ends of adjacent heel members on the one and other sides of the carrier tape are fused together.

17. The invention as recited in claim 16 wherein said carrier tape comprises a material containing thermoplastic fibers, and wherein the ends of adjacent heel members on the one and other sides of the carrier tapes are fused together by said carrier tape.

18. The invention as recited in claim 11 wherein said carrier tape has a plurality of spaced holes therethrough longitudinally aligned in parallel relationship with said longitudinal edge of said carrier tape. each of said holes being interposed between ends of adjacent heel members on the one and other sides of the carrier tape, and the ends of said adjacent heel members are bonded together through said holes.

19. The invention as recited in claim 18 wherein said filamentary stringer comprises a thermoplastic material and wherein ends of said adjacent heel members are fused together through said holes. 

1. In a threadless slide fastener chain, the combination comprising a carrier tape, a stringer formed from a filamentary material and having a plurality of head elements and a plurality of heel members interconnecting the plurality of head elements, said stringer being disposed along a longitudinal edge of the carrier tape with the plurality of heel members overlying a side surface of the carrier tape, said heel members having leg portions forming interstices therebetween, said carrier tape adjacent the longitudinal edge having portions projecting into the interstices of the stringer by at least one-half of the thickness of the portions of the filamentary material forming the heel portions, and each of said heel members being threadlessly bonded with the carrier tape whereby the stringer is firmly attached to the carrier tape.
 2. The invention as recited in claim 1 wherein said carrier tape comprises a material containing thermoplastic fibers.
 3. The invention as recited in claim 2 wherein said material is woven.
 4. The invention as recited in claim 2 wherein said material is nonwoven.
 5. The invention as recited in claim 2 wherein said filamentary stringer comprises a thermoplastic material, and wherein said heel members are fused with said carrier tape.
 6. The invention as recited in claim 1 wherein said projecting portions of the carrier tape are formed by displaced portions of the thickness of the carrier tape at regularly spaced intervals adjacent said longitudinal edge to conform to the interstices defined by each of said heel members.
 7. The invention as recited in claim 6 wherein said carrier tape is initially formed flat and subsequently deformed to produce the displaced portions.
 8. The invention as recited in claim 6 wherein said carrier tape is initially formed with the displaced portions.
 9. The invention as recited in claim 6 wherein said heel members are rigidly bonded to the projecting portions of the carrier tape.
 10. The invention as recited in claim 1 wherein said heel members are generally U-shaped to define bottom portions extending between adjacent leg portions of the heel members, and said leg portions and bottom portions of the heel members extend around the projecting portions of the carrier tape.
 11. In a threadless slide fastener chain, the combination comprising a carrier tape, a filamentary stringer having a plurality of head elements and a plurality of generally U-shaped heel members with leg portions interconnecting the plurality of head elements, said stringer being disposed along a longitudinal edge of said carrier tape with a first set of the plurality of heel members on one side of the carrier tape and with a second set of the plurality of heel members on the other side of the carrier tape, said filamentary stringer having first interstices between the leg portions of the first set of heel members and having second interstices between thE leg portions of the second set of heel members, said carrier tape adjacent the longitudinal edge having projecting portions extending into the first and second interstices by at least one-half of the thickness of the leg portions of heel members, each of said first and second sets of heel members being threadlessly bonded with said carrier tape whereby said filamentary stringer is firmly attached to said carrier tape such that the projecting portions of the carrier tape are retained in the first and second interstices.
 12. The invention as recited in claim 11 wherein said filamentary stringer and said carrier tape both comprise a thermoplastic material, and wherein said first and second sets of heel members are fused with said carrier tape.
 13. The invention as recited in claim 11 wherein said carrier tape is deformed at alternate spaced intervals to form the projecting portions extending into the respective first and second interstices.
 14. The invention as recited in claim 11 wherein said first and second sets of heel members are rigidly bonded to the projecting portions of said carrier tape.
 15. The invention as recited in claim 11 wherein the ends of adjacent heel members on the one and other sides of the carrier tape are bonded together through said carrier tape.
 16. The invention as recited in claim 15 wherein said filamentary stringer comprises a thermoplastic material, and wherein the ends of adjacent heel members on the one and other sides of the carrier tape are fused together.
 17. The invention as recited in claim 16 wherein said carrier tape comprises a material containing thermoplastic fibers, and wherein the ends of adjacent heel members on the one and other sides of the carrier tapes are fused together by said carrier tape.
 18. The invention as recited in claim 11 wherein said carrier tape has a plurality of spaced holes therethrough longitudinally aligned in parallel relationship with said longitudinal edge of said carrier tape, each of said holes being interposed between ends of adjacent heel members on the one and other sides of the carrier tape, and the ends of said adjacent heel members are bonded together through said holes.
 19. The invention as recited in claim 18 wherein said filamentary stringer comprises a thermoplastic material and wherein ends of said adjacent heel members are fused together through said holes. 